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2 years ago

An atom had a mass of 43 and it also has has 21 electrons

Chemistry

1 answer:

Serga [27]2 years ago

8 0

scandium. if you look up the number of electrons thats the periodic number and it gives you the answer

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35.0 mL of acid with an unknown concentration is titrated with 24.6 mL of 0.432 M base. What is the concentration of the acid? A

photoshop1234 [79]

Since we assume both reactants have 1 equivalent of H+ and OH- ions, we can balance the moles out. The acid of concentration x will have (x M)(0.035 L) = 0.035x moles of acid. Meanwhile, for the base: (0.432 M)(0.0246 L) = 0.0106 moles of base. Since these must be equivalent:
0.035x = 0.0106x = 0.304 M

8 0

2 years ago

PLEASE HELP, I'M BEGGING YOU!

Sloan [31]

Can I see a picture please so i can answer your question

6 0

2 years ago

Ocean water contains 3.5 nacl by mass. what mass of ocean water in grams contains 45.8 g of nacl

Romashka-Z-Leto [24]

Mass percentage of sodium chloride(NaCl) in ocean waters = 3.5 %

That means 3.5 g sodium chloride(NaCl) is present for every 100 g of ocean water.

The given mass of sodium chloride(NaCl) is 45.8 g

Calculating the mass of ocean waters that would contain 45.8 g sodium chloride(NaCl):

$45.8 g NaCl *\frac{100g ocean water}{3.5g NaCl}$

= 1309 g ocean water

Therefore, 45.8 g sodium chloride is present in 1309 g ocean water.

3 0

2 years ago

Explain the various modes of dispersal of seeds and fruits.

11Alexandr11 [23.1K]

There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus. Dispersal involves the letting go or detachment of a diaspore from the main parent plant.

Fruits and seeds dispersal is the process whereby fruits and seeds are scattered from their origin. The various ways by which fruit and seed are dispersed are known as agents of seed and fruit dispersal.

Check this link out for more information
https://qknowbooks.gitbooks.io/fruits-and-seeds/content/fruits_and_seeds_dispersal.html

4 0

2 years ago

The airbags that protect people in car crashes are inflated by the extremely rapid decomposition of sodium azide, which produces

Oxana [17]

Answer:

1. NaN₃(s) → Na(s) + 1.5 N₂(g)

2. 79.3g

Explanation:

<em>1. Write a balanced chemical equation, including physical state symbols, for the decomposition of solid sodium azide (NaN₃) into solid sodium and gaseous dinitrogen.</em>

NaN₃(s) → Na(s) + 1.5 N₂(g)

<em>2. Suppose 43.0L of dinitrogen gas are produced by this reaction, at a temperature of 13.0°C and pressure of exactly 1atm. Calculate the mass of sodium azide that must have reacted. Round your answer to 3 significant digits.</em>

First, we have to calculate the moles of N₂ from the ideal gas equation.

$P.V=n.R.T\\n=\frac{P.V}{R.T} =\frac{1atm.(43.0L)}{(0.08206atm.L/mol.K).286.2K} =1.83mol$

The moles of NaN₃ are:

$1.83molN_{2}.\frac{1molNaN_{3}}{1.5molN_{2}} =1.22molNaN_{3}$

The molar mass of NaN₃ is 65.01 g/mol. The mass of NaN₃ is:

$1.22mol.\frac{65.01g}{mol} =79.3g$

5 0

2 years ago